JP2021128036A - Gas concentration / humidity detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve measurement accuracy by measuring gas concentration and measuring humidity related to gas while avoiding an increase in size of an apparatus by using a simple configuration, and concentration and humidity related to gas in real time. Provided is a gas concentration / humidity detector capable of measuring. A gas concentration / humidity detection device (1) includes a sensor main body (10), a sensor base (30), and an insulating layer (20), and a concentration detection sensor of the sensor main body (10) includes two resistors and a concentration measurement. It has a lead wire 14 and a concentration measurement control circuit 40, and the humidity detection sensor of the sensor main body 10 measures the capacitance between the humidity measurement lead wire 15 and the humidity measurement lead wire 15 to be measured. A control circuit 50 for measuring humidity that detects the humidity of the gas is provided, and a part of the material that comes into direct contact with the gas to be measured is one of the insulating layer 20, the sensor base portion 30, and the sensor main body portion 10. , A humidity-sensitive material whose capacitance changes according to humidity. [Selection diagram] Fig. 1

Description

The present invention relates to a gas concentration / humidity detector.

In recent years, a fuel cell system, particularly a fuel cell system using a solid polymer membrane as an electrolyte, has been widely adopted as a vehicle power system. In order to achieve both improved fuel efficiency and improved durability of such a fuel cell system, it is necessary to optimize the amount of hydrogen supplied to the gas (hydrogen) used as fuel for the fuel cell in real time. ..

Further, in order to optimize the hydrogen supply amount, it is important to accurately measure the hydrogen concentration related to the gas to be measured. Conventionally, a technique for measuring a hydrogen concentration using a heat conduction type gas concentration sensor has been disclosed. In such a heat conductive gas concentration sensor, when the resistor comes into contact with a gas to be measured having a different hydrogen concentration, the measured concentration of the gas to be measured utilizes the difference in the amount of heat released by the resistor to the surroundings. Is being measured.

Here, the water content contained in the gas to be measured has a characteristic of being more easily condensed or evaporated depending on the temperature, as compared with nitrogen or the like contained in the gas to be measured. In other words, water (liquid water) tends to become water vapor by heating. On the other hand, the thermal conductivity of water vapor is smaller than that of hydrogen. Therefore, when water (liquid water) evaporates into water vapor, the amount of heat radiated to the periphery of the resistor of the heat conductive gas concentration sensor becomes small. Therefore, the hydrogen concentration of the gas to be measured detected by the heat conduction type gas concentration sensor becomes smaller than the actual hydrogen concentration of the gas to be measured, and a measurement error occurs. In response to such a problem related to measurement error, a gas sensor capable of measuring the concentration of water vapor related to the gas to be measured, that is, humidity, is adopted at the time of gas measurement.

For example, Patent Document 1 describes a heat-generating element that comes into contact with a gas to be measured mixed with a moist atmosphere, a power supply device that allows an electric current to flow through the heat-generating element, and a voltmeter that measures the voltage across the heat-generating element. It has a calculation unit that calculates and outputs the humidity and the concentration of the gas to be measured from the output voltage of the voltmeter. The voltage across the specified time is taken into the calculation unit, and the voltage across the heating element at the minimum applied current and the correction formula for the 0-point fluctuation and sensitivity fluctuation obtained in advance with the measured gas whose concentration is known are used to obtain other currents. The standardized output is obtained by correcting the value of the voltage across the heating element when flowing, and from the humidity correlation function using the difference between this standardized output and the voltage across the heating element at the minimum applied current as parameters. The humidity is obtained, and the 0-point fluctuation and sensitivity fluctuation due to the humidity of the standardized output are corrected from the two humidity correction value correlation functions that use the difference between the standardized output and the voltage across the heating element at the minimum applied current as parameters. Therefore, a gas sensor configured to output the humidity and the concentration of the gas to be measured by repeating the process of obtaining the concentration of the gas to be measured as one cycle is disclosed.

Japanese Unexamined Patent Publication No. 2005-300452

By the way, a detection device such as a gas sensor disclosed in Patent Document 1 changes the current in steps of three or more steps, and calculates the concentration and humidity of the gas to be measured from each output value.
However, in a detection device such as the gas sensor disclosed in Patent Document 1, it takes time to calculate the concentration and humidity of the gas to be measured. Therefore, in an environment where the gas concentration and humidity change from moment to moment, it is not possible to accurately calculate the humidity related to the gas to be measured in real time.

The present invention has been invented in view of such circumstances, and an object of the present invention is to measure the gas concentration and the humidity related to the gas by using a simple configuration and avoiding an increase in size of the apparatus. It is an object of the present invention to provide a gas concentration / humidity detection device capable of measuring the concentration and humidity of gas in real time while making it possible to improve the measurement accuracy.

One aspect of the present invention includes a sensor main body including a concentration detection sensor and a humidity detection sensor, a sensor base, and an insulating layer provided so as to come into contact with each of the sensor main body and the sensor base. It is a gas concentration / humidity detection device that detects the concentration and humidity of the gas to be measured in the gas measurement room, which is composed of an insulating layer, a sensor base part, and a sensor main body part. A current is applied to each of the two sensors so that the temperature difference between the two sensors is maintained at a predetermined value via the resistor, the concentration measurement lead wire connected to the two resistors, and the concentration measurement lead wire. It has a concentration measurement control unit that detects the concentration of the gas to be measured by measuring the voltage across each of the two resistors, and the humidity detection sensor comes into contact with the insulating layer. It has an insulating layer, a sensor base, and a sensor, which has a humidity measurement lead wire provided and a humidity measurement control unit that detects the humidity of the gas to be measured by measuring the electrostatic capacity between the humidity measurement lead wire. Some of the materials in the main body that come into direct contact with the gas to be measured are humidity-sensitive materials whose capacitance changes according to the humidity, and the capacitance between the humidity measurement leads is It is a gas concentration / humidity detection device that has the same capacitance as a part of the capacitance made of a moisture-sensitive material.

In the gas concentration / humidity detection device of the above aspect, the concentration detection sensor is used to detect the measured concentration of the gas to be measured, and the humidity detection sensor is used to detect the humidity related to the gas to be measured. In other words, the gas concentration / humidity detector can simultaneously measure the measured concentration and the measured humidity of the gas to be measured in real time. In this way, the presence or absence of measurement error can be determined using the measured humidity. Specifically, when the humidity is "0", there is no measurement error, and the measured concentration is the actual concentration of the gas to be measured. On the other hand, when there is humidity, there is a measurement error. Further, the higher the humidity, the larger the measurement error. In this case, the degree of influence of the measurement error on the measured concentration can be obtained from the magnitude of the humidity, and the actual concentration of the gas to be measured can be grasped.
Further, the configuration for measuring the humidity related to the gas concentration / humidity detection device is an insulating layer (or a sensor base portion and a sensor main body portion) composed of a humidity measurement lead wire, a humidity measurement control circuit, and a humidity sensitive material. Any one). Therefore, the gas concentration / humidity detection device uses a simple configuration to measure the gas concentration and the humidity at the same time.
Further, the humidity measurement lead wire for measuring the humidity is formed on the insulating film on which the concentration measurement lead wire of the concentration detection sensor is formed. Further, the insulating layer, the base portion, or the insulating film for measuring the humidity is originally a configuration for measuring the gas concentration of a general heat conduction type concentration measuring device. Therefore, the gas concentration / humidity detection device has two functions of concentration measurement and humidity measurement, but its dimensions and shape are not changed as compared with a general heat conduction type concentration measurement device. Therefore, the gas concentration / humidity detection device has realized that the size of the device can be avoided by adopting the humidity detection sensor.

According to the present invention, by using a simple configuration, while avoiding an increase in size of the apparatus, the gas concentration is measured and the humidity related to the gas is measured, so that the measurement accuracy can be improved and in real time. It is possible to provide a gas concentration / humidity detection device capable of measuring the concentration and humidity of gas.

It is an exploded view for demonstrating the structure of the gas concentration humidity detection apparatus which concerns on 1st Embodiment. It is a bottom view for demonstrating the structure of the gas concentration humidity detection apparatus which concerns on 1st Embodiment. FIG. 2 is a cross-sectional view taken along the line BB of FIG. It is a figure for demonstrating the control circuit for concentration measurement which concerns on 1st Embodiment. It is a bottom view for demonstrating the structure of the gas concentration humidity detection apparatus which concerns on 2nd Embodiment. FIG. 5 is a cross-sectional view taken along the line CC of FIG. It is a bottom view for demonstrating the structure of the gas concentration humidity detection apparatus which concerns on 3rd Embodiment. FIG. 7 is a cross-sectional view taken along the line DD of FIG. It is a bottom view for demonstrating the structure of the gas concentration humidity detection apparatus which concerns on 4th Embodiment. 9 is a cross-sectional view taken along the line EE of FIG. It is a figure for demonstrating the modification of the humidity measurement conducting wire which concerns on 1st Embodiment. It is a figure for demonstrating the modification of the humidity measurement conducting wire which concerns on 2nd Embodiment. It is a figure for demonstrating the modification of the humidity measurement conducting wire which concerns on 3rd Embodiment. It is a figure for demonstrating the modification of the insulating film which concerns on 1st to 4th Embodiment.

Embodiments of the present invention will be described below. In the description of the drawings below, the same or similar components are represented by the same or similar reference numerals. The drawings are examples, and the dimensions and shapes of the respective parts are schematic, and the technical scope of the present invention should not be limited to the embodiment.

[First Embodiment]
<Gas concentration / humidity detector 1>
First, the gas concentration / humidity detection device 1 according to the first embodiment will be described with reference to FIGS. 1 to 4. FIG. 1 is an exploded view for explaining the configuration of the gas concentration / humidity detection device 1 according to the first embodiment. FIG. 2 is a bottom view for explaining the configuration of the gas concentration / humidity detection device 1 according to the first embodiment. FIG. 3 is a cross-sectional view taken along the line BB of FIG. FIG. 4 is a diagram for explaining the concentration measurement control circuit 40 according to the first embodiment.

The gas concentration / humidity detection device 1 according to the first embodiment can measure the hydrogen supply amount in real time by using, for example, the hydrogen concentration of the gas supplied to the fuel cell system, which is used in the fuel cell system. It is a detection device that can be used. The gas concentration / humidity detection device 1 has a function of detecting the concentration of hydrogen constituting the gas to be measured and a function of detecting the concentration of water vapor contained in the gas, that is, the humidity.

In the following, for convenience of explanation, the concentration of hydrogen constituting the gas to be measured is referred to as "gas concentration" or "concentration", and the concentration of water vapor contained in the gas to be measured is referred to as "measured humidity" or "humidity". I may call it.

Further, as shown in FIGS. 1 and 3, the gas concentration / humidity detection device 1 includes the sensor main body portion 10, the insulating layer 20, and the sensor base portion 30 in the order from the second direction to the first direction in the stacking direction. To be equipped with. In other words, the insulating layer 20 is provided so as to come into contact with each of the sensor main body 10 and the sensor base 30 between the sensor main body 10 and the sensor base 30 in the stacking direction.

Further, as shown in FIGS. 2 and 3, the insulating layer 20, the inner surface of the sensor base portion 30, and a part of the sensor main body portion 10 (exposed from the opening 21 of the insulating layer 20 of the sensor main body portion 10 described later). The exposed portion 133) constitutes a gas measurement chamber 33 for accommodating the gas to be measured.

Hereinafter, for convenience of explanation, a state in which the sensor main body portion 10, the insulating layer 20, and the sensor base portion 30 are laminated to form the gas concentration / humidity detection device 1 may be referred to as a “laminated state”. Further, in the laminated state, the main surface on the first direction side in the stacking direction of each configuration of the gas concentration / humidity detection device 1 is called the "first main surface", and the main surface on the second direction side is called the "second main surface". May be called.

(Sensor body 10)
As shown in FIG. 1, the sensor main body 10 includes an insulating film 13, a first resistor 11, a second resistor 12, and a concentration measuring conductor 14 formed on the first main surface 131 of the insulating film 13. It also has a humidity measuring conductor 15, and a gas introduction passage 16 provided so as to penetrate the insulating film 13 in the thickness direction. Further, as shown in FIG. 2, the sensor main body 10 includes a concentration measurement control circuit 40, which is an example of a concentration measurement control unit, and a humidity, which is an example of a humidity measurement control unit, provided outside the insulating film 13. It has a measurement control circuit 50. Further, the sensor main body 10 may have a measurement result processing unit (not shown).

The insulating film 13 is, for example, a thin film made of polyimide. The thickness of the insulating film 13 is, for example, several μm to several tens of μm.

The first resistor 11 and the second resistor 12 are, for example, resistors composed of Pt. Further, as shown in FIGS. 1 and 2, the first resistor 11 and the second resistor 12 are arranged so that their respective longitudinal directions are along the lateral direction of the insulating film 13.

In the first embodiment, the first resistor 11 is a resistor for detecting the temperature of the gas to be measured, and the second resistor 12 is a resistor for detecting the concentration of the gas to be measured. Hereinafter, when the first resistor 11 and the second resistor 12 are not distinguished, the first resistor 11 and the second resistor 12 may be collectively referred to as "two resistors" or "resistors".

The concentration measuring conductor 14 is a metal conductor for supplying a current to each of the two resistors and measuring the resistance value or the voltage across the two resistors. The material of the concentration measuring conductor 14 is, for example, gold or copper.

Further, in the first embodiment, the resistance value or the voltage across the two resistors is measured by the four-terminal method. Therefore, the concentration measuring conductor 14 has eight metal conductors. Specifically, as shown in FIGS. 2 and 3, the concentration measurement conductors 14 are the first concentration measurement conductor 141 and the second resistor, which are provided at both ends of the first resistor 11. It has a second concentration measuring conductor 142 provided at each end of the twelve.

The humidity measurement conductor 15 is a metal conductor for measuring the capacitance of the insulating layer 20 that is in direct contact with the humidity measurement conductor 15. The material of the humidity measuring conductor 15 is, for example, gold or copper.

Further, as shown in FIGS. 2 and 3, the humidity measurement conductor 15 includes a first humidity measurement conductor 151 and a second humidity measurement conductor 152 configured to be parallel to each other. The distance between the first humidity measuring conductor 151 and the second humidity measuring conductor 152 is several tens of μm or more. This interval prevents a short circuit between the first humidity measuring conductor 151 and the second humidity measuring conductor 152.

Further, the capacitance between the first humidity measuring conductor 151 and the second humidity measuring conductor 152, that is, the capacitance between the humidity measuring conductor 15 is in direct or indirect contact with the humidity measuring conductor 15. It is the same as the capacitance of the component of the gas concentration / humidity detection device 1 having a capacitance. In the first embodiment, the capacitance between the humidity measuring conductors 15 is the same as the capacitance of the insulating layer 20 in direct contact with the humidity measuring conductors 15.

Further, as shown in FIGS. 2 and 3, the humidity measuring conductor 15 is located between the first density measuring conductor 141 and the second density measuring conductor 142 located on the center side of the insulating film 13 in the lateral direction. It is provided in. The humidity measuring conductor 15 may be provided at another position on the first main surface 131 of the insulating film 13.

The gas introduction passage 16 is a through hole communicating with the gas measurement chamber 33 for introducing the gas to be measured into the gas measurement chamber 33. Further, as shown in FIG. 1, the gas introduction passage 16 is provided between the first resistor 11 and the second resistor 12 in the lateral direction of the insulating film 13. Therefore, the gas introduction passage 16 can exert a function of preventing heat conduction between the first resistor 11 and the second resistor 12.

The concentration measurement control circuit 40 is connected to the first resistor 11 and the second resistor 12 via the concentration measurement lead wire 14. In this way, as shown in FIG. 2, the concentration measurement control circuit 40, the first resistor 11, the second resistor 12, and the concentration measurement conductor 14 determine the concentration of the gas to be measured according to the first embodiment. A concentration detection sensor 101 for detection is configured. The details of the concentration detection according to the concentration detection sensor 101 will be described later.

The humidity measurement control circuit 50 is connected to the humidity measurement lead wire 15. Thus, as shown in FIG. 2, the humidity measurement control circuit 50 and the humidity measurement conductor 15 constitute a humidity detection sensor 102 for detecting the humidity of the gas to be measured according to the first embodiment. The details of humidity detection by the humidity detection sensor 102 will be described later.

The measurement result processing unit has a configuration in which the actual concentration of the gas to be measured is calculated using the measured concentration measured by the concentration measurement control circuit 40 and the measured humidity measured by the humidity measurement control circuit 50. .. Specifically, the measurement result processing unit substitutes the measured concentration and the measured humidity into a mathematical formula expressing the relationship between the actual concentration of the gas to be measured and the measured concentration and the measured humidity, for example. Calculate the actual concentration of gas. The sensor main body 10 does not have to have a measurement result processing unit.

In the following, for convenience of explanation, the gas concentration measured by the concentration measurement control circuit 40, that is, the gas concentration that may contain a measurement error is referred to as "measurement concentration", and is referred to by the measurement result processing unit. The actual gas concentration of the processed gas to be measured, that is, the gas concentration in which the measurement error is corrected may be referred to as "actual gas concentration".

In this way, the gas concentration / humidity detection device 1 according to the first embodiment simultaneously measures the measurement concentration and the humidity of the gas to be measured to determine the presence / absence of a measurement error of the gas concentration (hydrogen concentration) due to the humidity. Above, the actual concentration of the gas to be measured can be accurately grasped.

(Insulation layer 20)
The insulating layer 20 has two functions of an insulating film and a moisture-sensitive film. The insulating layer 20 is a thin film having a thickness of several μm or less. In the laminated state, the insulating layer 20 is provided on the first main surface 131 of the insulating film 13. Further, in the laminated state, the portion of the insulating layer 20 located in the gas measurement chamber 33 comes into direct contact with the gas to be measured.

Further, as shown in FIG. 1, the insulating layer 20 has an opening 21 and a main body 22. In the laminated state, the opening 21 of the insulating layer 20 measures the gas so that the first resistor 11 and the second resistor 12, the gas introduction passage 16, and the exposed portion 133 are in direct contact with the gas to be measured. It is exposed in the room 33. Here, the exposed portion 133 is a part of the insulating film 13 around the first resistor 11 and the second resistor 12. At the same time, the main body 22 of the insulating layer 20 has a gas measuring chamber so as to insulate the concentration measuring conductor 14 and the humidity measuring conductor 15 and the portion of the insulating film 13 other than the exposed portion 133 from the gas to be measured. It is isolated from 33.

The material of the insulating layer 20 is a humidity-sensitive material such as polyimide or cellulose whose capacitance changes according to humidity. Therefore, the insulating layer 20 absorbs water vapor (humidity) contained in the gas to be measured, so that the capacitance becomes large. In other words, the higher the humidity of the gas to be measured, the larger the capacitance of the insulating layer 20. On the other hand, the lower the humidity of the gas to be measured, the smaller the capacitance of the insulating layer 20.

(Sensor base unit 30)
The sensor base portion 30 has a base film 31 which is a thin film and a frame-shaped spacer 32. In the laminated state, as shown in FIG. 2, the spacer 32 is the first main body of the insulating layer 20 so as to surround the first resistor 11 and the second resistor 12, the gas introduction passage 16, and the exposed portion 133. It is provided on the surface 201. Further, the base film 31 is provided on the first main surface 321 of the spacer 32 so as to cover the opening of the spacer 32.

In the first embodiment, the sensor base portion 30 has been described as having a thin base film 31 and a frame-shaped spacer 32, but the sensor base portion 30 is recessed in the thick base film 31. It may be an integrated configuration provided with.

In this way, in the laminated state, gas measurement is performed by the second main surface 312 of the base film 31, the inner peripheral surface 322 of the spacer 32, the first main surface 201 of the insulating layer 20, and the exposed portion 133 of the sensor main body 10. It constitutes a room 33. In other words, the second main surface 312 and the inner peripheral surface 322 of the sensor base portion 30, the first main surface 201 of the insulating layer 20, and the exposed portion 133 of the sensor main body portion 10 are introduced into the gas measurement chamber 33. This is the part that comes into direct contact with the gas to be measured.

<Concentration detection related to the concentration detection sensor 101>
Next, the concentration detection according to the concentration detection sensor 101 will be described in detail. Hereinafter, for convenience of explanation, a state in which the gas to be measured is introduced into the gas measurement chamber 33 and the concentration and humidity are measured by the concentration detection sensor 101 and the humidity detection sensor 102 may be referred to as a “measurement state”. ..

(Detection operation)
The concentration detection sensor 101 according to the first embodiment is an example of a heat conduction type sensor. The concentration detection sensor 101 is based on control by the concentration measurement control circuit 40, and utilizes the difference in the amount of heat released by the resistor to the surroundings when the resistor comes into contact with a gas to be measured having a different hydrogen concentration. Then, the measured concentration of the gas to be measured is measured.

Specifically, in the measurement state, the concentration measurement control circuit 40 supplies the first resistor 11 with a current I1 having a predetermined magnitude. When the current I1 is supplied to the first resistor 11, the temperature rise due to the IR loss of the first resistor 11 is negligible. On the other hand, at the same time, the concentration measurement control circuit 40 supplies the second resistor 12 with a current I2 larger than the current I1.

Here, in the measurement state, the second resistor 12 changes the amount of heat radiated to the surroundings due to the difference in the thermal conductivity of the components contained in the gas to be measured that comes into contact with the second resistor 12. To give an example, in the gas to be measured containing hydrogen and nitrogen, the thermal conductivity of hydrogen is about 7 times that of nitrogen. Therefore, as the hydrogen content of the gas to be measured, that is, the hydrogen concentration (gas concentration) increases, the amount of heat radiated to the periphery of the second resistor 12 increases.

As described above, when measuring the measured gas having a high hydrogen concentration (gas concentration) as compared with the measured gas having a low hydrogen concentration (gas concentration), the concentration measurement control circuit 40 uses the first resistor 11 and the first resistor 11 and the second. In order to maintain the temperature difference between the two resistors 12 at a predetermined value, the current I2 supplied to the second resistor 12 is controlled to be large.

In this way, the concentration detection sensor 101 measures the resistance value or the voltage across the second resistor 12 when the current I2 is supplied under the control of the concentration measurement control circuit 40 via the concentration measurement lead wire 14. By doing so, the hydrogen concentration of the gas to be measured is detected.

(Measurement error)
On the other hand, the water contained in the gas may become water vapor depending on the ambient temperature. As described above, the amount of heat radiated to the periphery of the second resistor 12 becomes small due to the generation of water vapor having a thermal conductivity smaller than that of hydrogen. Therefore, the hydrogen concentration of the gas to be measured detected by the concentration detection sensor 101 becomes smaller than the actual hydrogen concentration of the gas to be measured, and a measurement error occurs. Further, the higher the humidity in the gas measurement chamber 33, the larger the measurement error of the concentration detection sensor 101.

In response to such a measurement error, the gas concentration / humidity detection device 1 according to the first embodiment measures the concentration detection sensor 101 using the humidity detection sensor 102, and measures the humidity in the gas measurement room 33. To detect. Then, by using the detected humidity to understand the presence or absence of measurement error or the influence of the measurement error on the detection of the actual gas concentration, the measurement accuracy is improved and the concentration and humidity related to the gas are measured in real time. It is realized to do.

<Humidity detection related to humidity detection sensor 102>
Subsequently, the humidity detection according to the humidity detection sensor 102 will be described in detail.
The humidity detection sensor 102 according to the first embodiment is an example of a capacitance measuring instrument. The humidity detection sensor 102 measures the humidity in the measurement room by measuring the capacitance between the humidity measurement conductors 15 under the control of the humidity measurement control circuit 50.

Specifically, in the measurement state, the humidity measurement control circuit 50 measures the capacitance of the insulating layer 20 via the humidity measuring conductor 15 which is in direct contact with the insulating layer 20 to measure the capacitance of the insulating layer 20. Measure the humidity.

As described above, the insulating layer 20 is made of a moisture-sensitive material. Therefore, when the gas to be measured contains water vapor (humidity), the insulating layer 20 absorbs moisture. Therefore, the capacitance of the insulating layer 20 becomes large. As a result, the capacitance between the humidity measuring conductor 15 that is in direct contact with the insulating layer 20 also increases. In this way, the humidity detection sensor 102 detects the measured humidity using the measured capacitance between the measured humidity measuring conductors 15, that is, the capacitance of the insulating layer 20.

In the first embodiment, the humidity detection sensor 102 has been described as a configuration for measuring the capacitance of the insulating layer 20 formed of the humidity-sensitive material, which is in direct contact with the humidity measurement conductor 15. It is not limited to the content. The humidity detection sensor 102 may measure the capacitance of a configuration formed of a humidity-sensitive material other than the gas concentration / humidity detection device 1 that is in direct contact with the gas to be measured.

In other words, in the first embodiment, the structure in which the insulating layer 20 is formed of the moisture-sensitive material has been described, but the present invention is not limited to the above contents. Any one of the base film 31 of the sensor base portion 30, the spacer 32 of the sensor base portion 30, and the insulating film 13 of the sensor body portion 10 (particularly, the exposed portion 133), which are in direct contact with the gas to be measured described above. May be composed of a moisture sensitive material. In such a case, the capacitance of the base film 31, the spacer 32, or the insulating film 13 changes due to moisture absorption.

Further, the base film 31, the spacer 32, and the insulating film 13 are in direct or indirect contact with the insulating layer 20. Therefore, the humidity measuring conductor 15 is indirect contact with the base film 31, the spacer 32, and the insulating film 13 via the insulating layer 20. Therefore, the humidity detection sensor 102 measures the capacitance of the base film 31, the spacer 32, or the insulating film 13 made of the humidity-sensitive material via the humidity measurement conductor 15 to detect the measured humidity. Can be done.

When the measurement result processing unit is provided, the measurement result processing unit uses the measured humidity measured by the humidity detection sensor 102 to correct the measurement error due to the measured humidity, thereby correcting the actual concentration of the gas to be measured. Can be calculated.

As described above, the gas concentration / humidity detection device 1 according to the first embodiment detects the measured concentration of the gas to be measured by using the concentration detection sensor 101, and detects the humidity related to the gas to be measured by using the humidity detection sensor 102. To detect. In other words, the gas concentration / humidity detection device 1 can simultaneously measure the measured concentration and the measured humidity of the gas to be measured in real time. In this way, the presence or absence of measurement error can be determined using the measured humidity. Specifically, when the humidity is "0", there is no measurement error, and the measured concentration is the actual concentration of the gas to be measured. On the other hand, when there is humidity, there is a measurement error. Further, the higher the humidity, the larger the measurement error. In this case, the degree of influence of the measurement error on the measured concentration can be obtained from the magnitude of the humidity, and the actual concentration of the gas to be measured can be grasped.
Further, the configuration for measuring the humidity of the gas concentration / humidity detection device 1 includes a humidity measurement lead wire 15, a humidity measurement control circuit 50, and an insulating layer 20 (or a base film 31) composed of a humidity sensitive material. Either one of the spacer 32 and the insulating film 13). Therefore, the gas concentration / humidity detection device 1 uses a simple configuration to measure the gas concentration and the humidity at the same time.
Further, the humidity measurement lead wire 15 for measuring the humidity is formed on the insulating film 13 on which the concentration measurement lead wire 14 of the concentration detection sensor 101 is formed. Further, the insulating layer 20, the base film 31, the spacer 32, or the insulating film 13 for measuring the humidity is originally a configuration for measuring the gas concentration of a general heat conduction type concentration measuring device. Therefore, the gas concentration / humidity detection device 1 has two functions of concentration measurement and humidity measurement, but its dimensions and shape are not changed as compared with a general heat conduction type concentration measurement device. Therefore, the gas concentration / humidity detection device 1 has realized that it is possible to avoid an increase in size of the device by adopting the humidity detection sensor 102.
When the measurement result processing unit is provided, the gas concentration / humidity detection device 1 uses the detected measurement concentration and measurement humidity to correct the measurement error due to the measurement humidity and calculate the actual concentration of the gas to be measured. be able to.

That is, in the first embodiment, by adopting the humidity detection sensor 102 and the insulating layer 20 (or any one of the base film 31, the spacer 32, and the insulating film 13), the gas is used in a simple configuration. While avoiding the increase in size of the concentration / humidity detection device 1, the gas concentration is measured and the humidity related to the gas is measured to improve the measurement accuracy while measuring the concentration and humidity related to the gas in real time. It is possible to provide a gas concentration / humidity detection device that can realize the above.

[Second Embodiment]
Subsequently, the gas concentration / humidity detection device 1 according to the second embodiment will be described in detail with reference to FIGS. 5 and 6. FIG. 5 is a bottom view for explaining the configuration of the gas concentration / humidity detection device 1 according to the second embodiment. FIG. 6 is a cross-sectional view taken along the line CC of FIG.

The gas concentration / humidity detection device 1 according to the second embodiment has a different configuration of the humidity measurement lead wire 15 from the first embodiment. Therefore, in the following, the description of the matters common to the first embodiment of the second embodiment will be omitted, and the different points, that is, the configuration of the humidity measurement conducting wire 15 according to the second embodiment will be described. In particular, the same action and effect due to the same configuration are not mentioned.

The humidity measurement conductor 15 according to the second embodiment includes a first humidity measurement conductor 151 and a second humidity measurement conductor 152. On the other hand, unlike the first embodiment, as shown in FIGS. 5 and 6, the first humidity measurement lead wire 151 utilizes one of the concentration measurement lead wires 14 (first concentration measurement lead wire 141). ing. In other words, the first concentration measuring conductor 141 has a function of a conductor used for concentration measurement and a function of a conductor used for humidity measurement.

By adopting the humidity measurement conductor 15 having the configuration according to the second embodiment, the total number of the humidity measurement conductor 15 and the concentration measurement conductor 14 can be reduced. Therefore, it is possible to simplify the configuration of the gas concentration / humidity detection device 1 and reduce the manufacturing cost of the gas concentration / humidity detection device 1.

[Third Embodiment]
Subsequently, the gas concentration / humidity detection device 1 according to the third embodiment will be described in detail with reference to FIGS. 7 and 8. FIG. 7 is a bottom view for explaining the configuration of the gas concentration / humidity detection device 1 according to the third embodiment. FIG. 8 is a cross-sectional view taken along the line DD of FIG.

The gas concentration / humidity detection device 1 according to the third embodiment has a different configuration of the humidity measurement lead wire 15 from the first embodiment. Therefore, in the following, the description of the matters common to the first embodiment of the third embodiment will be omitted, and the different points, that is, the configuration of the humidity measurement conducting wire 15 according to the third embodiment will be described. In particular, the same action and effect due to the same configuration are not mentioned.

The humidity measurement conductor 15 according to the third embodiment includes a first humidity measurement conductor 151 and a second humidity measurement conductor 152. On the other hand, unlike the first embodiment, as shown in FIGS. 7 and 8, the first humidity measurement conductor 151 utilizes one of the concentration measurement conductors 14 (first concentration measurement conductor 141). The second humidity measurement conductor 152 uses the other one (second concentration measurement conductor 142) of the concentration measurement conductor 14. In other words, in the third embodiment, a part of the concentration measurement conductor 14 is also used as the humidity measurement conductor 15.

By adopting such a configuration in which a part of the concentration measurement conductor 14 is also used as the humidity measurement conductor 15 according to the third embodiment, it is not necessary to newly adopt the humidity measurement conductor 15. Therefore, the configuration and manufacturing process of the gas concentration / humidity detection device 1 can be further simplified, and the manufacturing cost of the gas concentration / humidity detection device 1 can be further reduced.

[Fourth Embodiment]
Subsequently, the gas concentration / humidity detection device 1 according to the fourth embodiment will be described in detail with reference to FIGS. 9 and 10. FIG. 9 is a bottom view for explaining the configuration of the gas concentration / humidity detection device 1 according to the fourth embodiment. FIG. 10 is a cross-sectional view taken along the line EE of FIG.

The gas concentration / humidity detection device 1 according to the fourth embodiment has a different configuration of the humidity measurement lead wire 15 from the first embodiment. Therefore, in the following, the description of the matters common to the first embodiment of the fourth embodiment will be omitted, and the different points, that is, the configuration of the humidity measurement conducting wire 15 according to the fourth embodiment will be described. In particular, the same action and effect due to the same configuration are not mentioned.

The humidity measurement conductor 15 according to the fourth embodiment includes a first humidity measurement conductor 151 and a second humidity measurement conductor 152. On the other hand, unlike the first embodiment, as shown in FIG. 10, the first humidity measuring conductor 151 and the second humidity measuring conductor 152 sandwich the insulating layer 20 from both sides in the thickness direction of the insulating layer 20. It is provided. Therefore, when the gas concentration / humidity detection device 1 is viewed from the bottom, as shown in FIG. 9, the first humidity measurement lead wire 151 and the second humidity measurement lead wire 152 are provided so as to overlap each other.

Here, in the first embodiment, the first humidity measuring conductor 151 and the second humidity measuring conductor 152 are provided between the insulating film 13 and the insulating layer 20 in the stacking direction. In this case, in order to prevent a short circuit between the first humidity measurement conductor 151 and the second humidity measurement conductor 152, the first humidity measurement conductor 151 and the second humidity measurement conductor 152 according to the first embodiment are combined. The interval is several tens of μm or more.

On the other hand, in the fourth embodiment, the first humidity measuring conductor 151 and the second humidity measuring conductor 152 are provided on both sides of the insulating layer 20 in the thickness direction. Therefore, the isolation of the insulating layer 20 does not cause a short circuit between the first humidity measuring conductor 151 and the second humidity measuring conductor 152. The insulating layer 20 is a thin film having a thickness of several μm or less. Therefore, the distance between the first humidity measuring conductor 151 and the second humidity measuring conductor 152 according to the fourth embodiment provided in this way is several μm or less. That is, the distance between the first humidity measurement conductor 151 and the second humidity measurement conductor 152 according to the fourth embodiment is set between the first humidity measurement conductor 151 and the second humidity measurement conductor 152 according to the first embodiment. Is smaller than the interval between.

By adopting the humidity measurement conductor 15 having the configuration according to the fourth embodiment, the distance between the first humidity measurement conductor 151 and the second humidity measurement conductor 152 is different from that of the first embodiment. Can be shortened. In other words, the first humidity measuring conductor 151 and the second humidity measuring conductor 152 can be brought close to each other. Therefore, the accuracy of humidity measurement by the gas concentration / humidity detection device 1 can be improved.

[Other variants]
Subsequently, with reference to FIGS. 11 to 14, a modified example of the humidity measuring conductor 15 according to the first to third embodiments and a modified example of the insulating film 13 according to the first to fourth embodiments will be described in detail. explain. FIG. 11 is a diagram for explaining a modified example of the humidity measuring conductor 15 according to the first embodiment. FIG. 12 is a diagram for explaining a modified example of the humidity measuring conductor 15 according to the second embodiment. FIG. 13 is a diagram for explaining a modified example of the humidity measurement conducting wire according to the third embodiment. FIG. 14 is a diagram for explaining a modification of the insulating film 13 according to the first to fourth embodiments.

In the following description, the description of the matters common to the first to fourth embodiments will be omitted, and the differences will be described. In particular, the same action and effect due to the same configuration are not mentioned.

In the first to third embodiments, the humidity measurement conductors 15 are parallel, the first humidity measurement conductor 151 and the second humidity measurement conductor 152, that is, the intervals are uniform along the longitudinal direction. Although it has been described as being composed of the first humidity measuring conductor 151 and the second humidity measuring conductor 152, the present invention is not limited to the above configuration. For example, as shown in FIGS. 11 to 13, a part of the interval portion in the longitudinal direction of the first humidity measurement conductor 151 and the second humidity measurement conductor 152 may be formed narrower than the other intervals. In other words, the humidity measuring conductor 15 may have a narrow interval portion having a narrow interval and a wide interval portion having a wide interval.

In this way, the humidity measurement conductor 15 employs the first humidity measurement conductor 151 and the second humidity measurement conductor 152 provided between the insulating film 13 and the insulating layer 20 in the stacking direction, and has a wide interval. As a result, it is possible to prevent a short circuit between the first humidity measuring conductor 151 and the second humidity measuring conductor 152, and to improve the humidity measurement accuracy due to the narrow interval.

Further, in the first to fourth embodiments, the insulating film 13 has been described as having a uniform thickness in the thickness direction, but the insulating film 13 is not limited to the above configuration. For example, the second main surface 132 of the insulating film 13 may have a recess. Specifically, as shown in FIG. 14, even if a thin portion 130 formed thinner than the other portions is provided at a position of the second main surface 132 of the insulating film 13 facing the gas measurement chamber 33. good.

With such a thin portion 130, the amount of water vapor contained in the gas to be measured in the gas measuring chamber 33 can be reduced by the insulating film 13. Therefore, it is possible to improve the responsiveness of the gas concentration / humidity detection device 1.

The embodiments described above are for facilitating the understanding of the present invention, and are not for limiting and interpreting the present invention. Each element included in the embodiment and its arrangement, material, condition, shape, size, and the like are not limited to those exemplified, and can be changed as appropriate. In addition, the configurations shown in different embodiments can be partially replaced or combined.

1 ... Gas concentration / humidity detector, 10 ... Sensor body, 11 ... 1st resistor, 12 ... 2nd resistor, 13 ... Insulation film, 14 ... Concentration measurement lead wire, 15 ... Humidity measurement lead wire, 16 ... Gas Introduction passage, 20 ... Insulation layer, 30 ... Sensor base part, 31 ... Base film, 32 ... Spacer, 33 ... Gas measurement room, 40 ... Concentration measurement control circuit, 50 ... Humidity measurement control circuit, 60 ... Control unit, 141 ... 1st concentration measurement lead wire, 142 ... 2nd concentration measurement lead wire, 151 ... 1st humidity measurement lead wire, 152 ... 2nd humidity measurement lead wire

Claims (1)

The insulating layer includes a sensor main body including a concentration detection sensor and a humidity detection sensor, a sensor base, and an insulating layer provided so as to come into contact with each of the sensor main body and the sensor base. A gas concentration / humidity detection device that detects the concentration and humidity of the gas to be measured in the gas measurement chamber composed of the sensor base and the sensor body.
The concentration detection sensor is provided with two resistors exposed in the gas measurement chamber, a concentration measurement lead wire connected to the two resistors, and a temperature of the two resistors via the concentration measurement lead wire. Concentration measurement that detects the concentration of the gas to be measured by supplying a current to each of the two resistors so that the difference is maintained at a predetermined value and measuring the voltage across each of the two conductors. Has a control unit,
The humidity detection sensor is a humidity measurement control that detects the humidity of the gas to be measured by measuring the capacitance between the humidity measurement lead wire provided so as to be in contact with the insulating layer and the humidity measurement lead wire. With a part,
Of the insulating layer, the sensor base portion, and the sensor main body portion, a part of the material that comes into direct contact with the gas to be measured is a humidity-sensitive material whose capacitance changes according to humidity.
The capacitance between the humidity measuring conductors is the same as the partial capacitance made of the moisture-sensitive material.
Gas concentration / humidity detector.

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